Answer:
The distilled water will be boiled faster as it does not contain any non - volatile solute.
- The salty water contains different non - volatile salts in it.
- Due to the presence of these salts, its vapour pressure will be decreased and boiling point will be elevated.
- So, salty water will take more time to boil.
- On the other hand, distilled water does not have any such solute and due to this its vapour pressure will not be affected.
- Hence, it will boil fast than salty water.
B. new crusts move at midocean ridges
C. tectonic movements cause hotspot volcanism
D. mountains are created along cracks in Earth plates
Answer:d
Explanation:test
B) The weight of the rock.
C) The hardness of the rock.
D) The composition of the rock.
Answer:
Its D.
Explanation:
I just took a usatestprep on it and it had the same question.
According to the concept of Avogadro's number, there are 1.505×10²³ molecules in 0.25 mole of O₂.
Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.
It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .
According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.
Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number
Number of molecules is obtained by multiplying number of moles and Avogadro's number , that is 0.25×6.023×10²³=1.505×10²³ molecules.
Thus, there are 1.505×10²³ molecules in in 0.25 mole of O₂.
Learn more about Avogadro's number,here:
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Which statement describes what occurs during
this reaction?
(1) Energy is absorbed as a bond is formed.
(2) Energy is absorbed as a bond is broken.
(3) Energy is released as a bond is formed.
(4) Energy is released as a bond is broken.
Answer: The correct option is 2.
Explanation: We are given in the question that Fluorine molecule is dissociating into two Fluorine atoms. Equation for the following is given by:
In a chemical reaction if the energy is written at the reactant side, the energy is being absorbed and if the energy is written at the product side, the energy is being released.
From the given chemical equation, the energy is written at the reactant side, so the energy is being absorbed by the reactants in order to break the bond between molecule to form 2 individual Fluorine atoms.
Hence, the correct option is 2.